MP-WFRFT系统中8PSK星座裂变图案分析

In order to further explore the effect of multiple parameters weighted fractional Fourier transform (MP-WRFRT) on the higher order baseband modulations, the quantitative and qualitative research on 8PSK constellation splitting in WFRFT-based systems were carried out. The constellation splitting function was defined, and the corresponding geometry model was also established. Based on the vector composition method, the 8PSK constellation splitting criteria was obtained in MP-WFRFT-based systems. By analyzing the relationship between combined vector and constellation superposition, it was deduced that there was one-to-one correspondence between the magnitude ratio of different MP-WFRFT's time-domain coefficients and the number of constellation points. The constellation splitting system based on MP-WFRFT was proposed, then the number of constellation splitting points and blurring factors were used to properly decide the MP-WFRFT's parameters. The corresponding mixed integer program was also built and the Genetic Algorithm (GA) was adopted to solve the optimal program. Simulation results demonstrated that the basic splitting patterns, the number of splitting points and the blurring rule were all in accord with the basic 8PSK constellation splitting criteria in MP-WFRFT-based systems. Besides, the bit error rate (BER) performance comparisons also showed that the unauthorized receiver's performance was degraded while the authorized receiver's communication quality was maintained well in the MP-WFRFT-based systems. MP-WFRFT can make the original baseband signals achieve a good performance on the anti-energy detection and anti-constellation recognition, which can further improve the system's anti-interception ability, and can be implemented in the secure communications.